Negative impacts of rainfall on Aquarius Sea Surface Salinity measurements

The remote sensing of Sea Surface Salinity (SSS) by the Aquarius L-band radiometer is a very challenging task. This paper describes one particular challenge, namely to remove the effects of rain contamination on the measurement of ocean surface brightness temperature. Instantaneously, rain drops striking the ocean increases the surface roughness that raises the ocean surface brightness temperature and that results in a corresponding reduction of the retrieved SSS. Moreover, over time periods of hours, rain accumulation can produce a fresh water lens that modifies the ocean brightness, which also affects the retrieved ocean salinity. This paper investigates these negative effects of instantaneous and accumulated rainfall on Aquarius SSS measurement.